The manufacture of memory disks, as is well known, comprises coating by sputtering both sides of an aluminum or other suitable material blank with magnetic material such as an alloy of cobalt, nickel and chromium. The disk blank contains a central aperture which, in use, is mounted on the spindle of a disk drive. The manufacture entails transporting one or more disks held horizontally or vertically in a carrier panel past a pair of spaced horizontal or vertical electrodes where a plasma of material generated by the electrodes is sputtered on the disk opposed surfaces. As described in the first related patent application, it is desirable to prevent cross-contamination of material from one of the opposed electrodes during sputtering simultaneously from both electrodes. The related applications describe means for isolating the peripheral edges of each disk in a carrier panel and the central aperture of the disk so that there is effectively no cross-communication of sputtered particles from one side of the disk to the other. Originally, loading and unloading of disks was a hand operation where the disks were mounted on a carrier panel. In some instance no closure device was present for the disk central aperture. In other operations a suitable flap or screw plug was provided to temporarily close off each disk central aperture during the sputtering step. In other equipment, disks are first coated on one side and then after removal from a panel are flipped and reinserted so that the other side of the disk can be coated in a subsequent sputtering step.
The above systems are typified by the sputtering and disk handling systems of ULVAC of Japan, CPA Inc. of Milpitas, Calif. and Leybold-Haraeus Vacuum Products of Export, PA. The disk loading and unloading to and from the panel in these systems were designed mainly for manual loading and unloading.